甘肃凹凸棒石对土壤Cd污染的钝化修复研究

以甘肃靖远、天水、临泽、西和、会宁5个地区的凹凸棒石为土壤重金属钝化材料,对Cd污染土壤进行钝化修复研究。结果表明,甘肃地区凹凸棒石作钝化剂可改善Cd污染土壤的理化性质,增加污染土壤中Cd的残渣态含量,降低Cd的生物有效性。临泽地区凹凸棒石钝化土壤中Cd的残渣态含量最高,比未钝化土壤增加40.0%;Cd的生物有效态含量最低,DTPA萃取态和TCLP萃取态分别为0.82 mg/kg和0.86 mg/kg,相比未钝化土壤降低21.9%和9.5%。甘肃凹凸棒石显著降低Cd毒性,降低植物重金属富集量,促进植物生长。临泽凹凸棒石和会宁凹凸棒石作钝化剂玉米地上和地下部分Cd最小富集量分别为0.18 mg/kg和0.52 mg/kg。甘肃凹凸棒石对重金属Cd钝化效果显著,其中临泽凹凸棒石钝化修复效果最好。

Stabilizing Remediation of Soil Contaminated by Cd Applying Gansu Attapulgite

In this study,Jingyuan,Tianshui,Linze,Xihe and Huining attapulgites were used as the stabilization to passivate Cd of contaminated soil.The results showed that attapulgite could improve the physical and chemical properties of Cd contaminated soil,increase the residual content of Cd in contaminated soil,and reduce the bioavailability of Cd.The residual Cd content in Linze attapulgite stabilized soil was significantly higher than that of other treatments,which was 40.0%higher than that of the control.The bioavailable Cd content in Linze attapulgite contaminated soil was the lowest,which was 0.82 mg/kg and 0.86 mg/kg,respectively,which was 21.9%and 9.5%lower than that of the control.Attapulgite of Gansu can significantly reduce the toxicity of heavy metals,reduce the accumulation of heavy metals in plants,and promote plant growth.When Linze attapulgite and Huining attapulgite were used as a stabilizer,the minimum Cd concentration in aboveground and underground parts of maize was 0.18 mg/kg and 0.52 mg/kg,respectively.Gansu attapulgite has a significant effect of stabilization on Cd,and Linze attapulgite has the best stabilized effect.